<html lang="en">
<head>
  <meta charset="UTF-8">
  <title>表单绑定-修饰符.number</title>
  <script type="text/javascript" src="vue.js"></script>
</head>
<body>
  <div id="app">
    <input v-model.number="age" type="number">
    <span>{{age}}</span>
  </div>
  <script>
    let vm = new Vue({
      el:"#app",
      data: {
        age: '',
      },
      watch: {
        age() {
          console.log(typeof(this.age))
        }
      }
    })
  </script>
</body>
</html>